Caish

Hey,
Who of you has replaced the stock timing set in the 4.0?
You know Mom got the XJ hot and it quit running.
I went over and hit the key and started but now rattles, was running rough like it was out of time. But no smoke like it was blowed.
Does the OEM timing chain (hard to belive it is with 255k miles but) gear on the cam use the plastic ring on aluminum gear?

I'm starting to think that maybe it got hot enough to compromise the old plastic and it jumped time. If that is the case it will save me several hours labor in fixing.

So does the 4.0 use a fiber/metal OEM gear?

91familyxj

I got a new timing set and it was metal gears.If you jumped timing I would be worried about a pistion hitting a valve. Do a comp. check

Caish

Very few Pushrod engines are interference engines. So that is not a big concern. 99% of all aftermarket gear sets are metal.

So the question still stands.

kriebz

I haven't taken mine apart, but my brother's YJ 4.2 had plastic coated gears.

J C George

I have seen 2 gears go right thru the oil pan ooo watch out....

Caish

The wifes XJ started this morning without fain fair.
Strange enough no rattle this morning, but you knew there was a butt in there didn't you, its running on what sounds like 4 cylinders now.
After about 15 minutes of warming up, I had the cap off the radiator and gave it a rev or two and it belched out coolant and bubbles.
So there is a cracked head or blown head gasket, I lean towards the craked head.
I revved it a few more times promptly started filling the shop with smoke.
So its a write off. I'm not going rebuild it.
Car shopping for another XJ now.
I'm leaning towards this one.

Power everything, 4.0 211k miles in the $1500 range.
3" Lift and no rust (its an Arkansas thing) new tires.

smokinlib1

It overheated, you blew a head gasket and/or cracked a head and you're going to junk it and buy another???
Let's see, you don't want to spend-$495 for a new head from Alabama Cylinder Head or $1200 for a rebuilt long block off E-Bay but you'll buy another for $1500....I really need find guys like you around here!

Caish

You hadn't seen the XJ, its been wrecked at least once, rebuilt it, changed the whole interior, but its still got some uni-body damage.
Its not a sparkling example of an XJ, its a well used machine.

BTW I don't trust anyone else to build my engine, I've been building them for 25 years since I did my first one.

So get over it. There is more o the story than it appears.
Its a 100+ right now and I'm suffering heat stroke in my shop to work on it.
Then when you add in the cost of your $1200 engine, Aluminum wheels, Lift Kit, New tires, Power Windows, Locks, I think its even got power seats, new stereo etc. the $1500 rig is a better deal rebuilding a tired 260k mile jeep that is a bastardization of two more.
Thanks for your opinion NOT. But your entitled to it.

smokinlib1

Wow what a effing little attitude you have